Anorexia Nervosa (AN) is a serious psychiatric illness characterized by a relentless but irrational concern about becoming fat, and extreme distortions in the perception of body shape and weight. The eating-related thoughts and behaviors of individuals with AN are repetitive, stereotyped, and extremely resistent to change, even after weight normalization. The persistence of these patterns of thought and behavior are likely related to the high relapse rate seen in this illness. The purpose of this Mentored Patient-Oriented Research Career Development Award (MPORCDA) is to develop and execute a program of research investigating neurocognitive processes in AN, focusing on implicit learning. The broad aim is to explore whether individuals with AN have a disturbance in implicit learning that may constitute a vulnerability to the development of AN and its persistence. The research supported by this award will examine the specific hypothesis that 1) patients with AN have a deficit in implicit learning and are particularly impaired at shifting responses when contingencies change;2) these disturbances persist, albeit to a lesser degree, even after short-term weight recovery;3) performance on implicit learning tasks correlates with clinical course;3) abnormalities in implicit learning are correlated with neural circuitry abnormalities, similar to those seen in OCD;4) improvement in cognitive deficits in weight restored patients is associated with improved clinical course. A fuller understanding of the basis of the remarkable persistence of the disordered thought and behavior characteristics of AN should provide a foundation for the development of more effective treatments. Under the strong mentorship of Dr. B. Timothy Walsh (for clinical research training and expertise in Anorexia Nervosa), Dr. Yaakov Stern (for training in cognitive neuroscience), and Dr. Bradley Peterson (for training in functional neuroimaging) this MPORCDA will provide the principal investigator with the skills and further research experience to apply advances in translational cognitive neuroscience to the study of AN. The long- term goal of this award is for the candidate to become an expert and independent researcher focusing on mechanisms underlying the development and persistence of eating disorders, with special application to anorexia nervosa.